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Ephemeris for Friday, November 29th. The sun will rise at 7:57. It’ll be up for 9 hours and 7 minutes, setting at 5:04. The moon, 3 days before new, will rise at 5:02 tomorrow morning. | A funny thing happened to Comet ISON on its way to perihelion yesterday. It’s nucleus disappeared. It was dimming all morning as it approached the sun. Most of this was visible in the SOHO LASCO C3 and C2 views. The comet was also visible from the STEREO spacecraft currently on the other side of the sun. These cameras are called chronographs because they hide the bright face of the sun with a disk called an occulting disk. Just before the head of the comet was to disappear behind the disk, it disappeared all by it self, what was left was it’s tail. However later something emerged from behind the disk where the comet was supposed to be. I’m guessing it’s the large cloud of debris from the nucleus.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Comet ISON or what’s left of it leaving the sun at 7:07 p.m. (EST) November 28, 2013. Credit NASA/ESA/SOHO LASCO C3. Annotation: mine.

Ephemeris for Thanksgiving Day, Thursday, November 28th. The sun will rise at 7:55. It’ll be up for 9 hours and 8 minutes, setting at 5:04. The moon, 3 days past last quarter, will rise at 3:53 tomorrow morning.

This is T minus Zero day for Comet ISON. At 1:35 this afternoon it will pass perihelion, its closest point to the sun, only a bit more than the sun’s diameter above the bright ball of the sun’s photosphere. It’s will look closer than that because the comet will be slightly behind the sun. It will still be visible in the Solar Dynamic Observatory’s telescopes. To check on the comet throughout the day go on the Internet go to spaceweather.com at the page bottom click on STEREO, then click on Latest Images You can call up the Solar Dynamics Observatory (SDO) and the SOHO LASCO images, or go to bobmoler.wordpress.com. I’m sure by tomorrow there will be time-lapse movies on Universe Today.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

There is a NASA sponsored Google + Hangout that will be transmitted on all NASA TV channels.

Ephemeris for Wednesday, November 27th. The sun will rise at 7:54. It’ll be up for 9 hours and 10 minutes, setting at 5:05. The moon, 2 days past last quarter, will rise at 2:46 tomorrow morning.

Let’s see where the bright planets are this eventful week. Venus is brilliant in the southwest after sunset. It will set at 7:53 p.m. The giant planet Jupiter will rise at 8:01 p.m. in the east northeast. It’s cruising against the stars of Gemini now. It will pass due south at 3:38 a.m. Mars will rise at 1:47 a.m. also in the east northeast. Reddish Mars is midway between Regulus in Leo and Spica in Virgo and tomorrow morning will be about 12 moon diameters above left of the moon. Mercury and Saturn will be together in the east southeast by 7 a.m. Mercury is the lower and brighter of the two. Comet ISON is now too close to the sun to be seen. Check bobmoler.wordpress.com (see below) for how to view Comet ISON near the sun.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Venus as it should appear at 6 p.m. on 11/27/2013. Created using Stellarium.

Telescopic view of Venus as it should appear at 6 p.m. on 11/27/2013. Created using Stellarium.

Jupiter and some winter constellations as they should appear at 10 p.m. on 11/27/2013. Created using Stellarium.

Telescopic view of Jupiter and its satellites as they should appear at 10 p.m. on 11/27/2013. The satellite Io is behind the planet and won’t appear until after midnight. Created using Stellarium.

The morning planets Mars, Saturn and Mercury plus the Moon at 6:45 a.m. November 28, 2013. Created using Stellarium

The Moon at 6:45 a.m. November 28, 2013. Created using Stellarium.

Comet ISON

Phil Plait the Bad Astronomer reported Monday that Comet ISON had suddenly decreased the amount of ices that it was emitting and pretty much simultaneously greatly increased the amount of dust it was producing. One of the possible explanations was that its nucleus had been disrupted. The comet’s nucleus is the small, maybe 2 km diameter, solid part of the comet. All the other parts of the comet are the thin ejected gas and dust from that nucleus. The head and tail of the comet is still a pretty good vacuum by earthly standards. There is still questions about it today. Here’s a YouTube video posted by the Planetary Society’s Emily Lakdawalla created by Emily from images taken by the STEREO Ahead spacecraft. It seems to be holding its own:

At the time of this posting (10 p.m. 11/26) the STEREO Behind COR 2 image shows Comet ISON entering on the lower left. Also SOHO’s LASCO C3 imager shows Comet ISON entering the view from the lower right. There’s also a coronal mass ejection (CME) erupting toward the comet. It could pass behind it, in front of it or actually toward it. It should be interesting.

Ephemeris for Tuesday, November 26th. The sun will rise at 7:53. It’ll be up for 9 hours and 12 minutes, setting at 5:05. The moon, 1 day past last quarter, will rise at 1:42 tomorrow morning.

Comet ISON is now invisible from the earth, being too close to the direction of the sun to be seen. However it is and will be in view of NASA’s fleet of solar observation spacecraft at least until the end of the month. The comet is already in view of the STEREO Ahead spacecraft, looking back toward the Earth and Mercury. Later tonight of early tomorrow it will be in the view of the Solar and Heliospheric Observatory or SOHO parked a million miles sun-ward from the earth. It will appear on the LASCO C3 imager first. Thursday it will also be visible to the Solar Dynamics Observatory or SDO. On the Internet go to spaceweather.com at the page bottom click on STEREO, then click on Latest Images, or go to bobmoler.wordpress.com.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Animation of Comet ISON rounding the sun on Thanksgiving Day, November 28, 2013. Created using Cartes du Ciel (Sky Charts).

Ephemeris for Monday, November 25th. The sun will rise at 7:52. It’ll be up for 9 hours and 14 minutes, setting at 5:06. The moon, at last quarter today, will rise at 12:40 tomorrow morning.

Comet ISON, a bit more than 4 days from its closest approach to the sun on Thanksgiving Day, is now well within the orbit of Mercury only 22 million miles from the sun. The comet should be hard to spot this morning. It rises at 6:58 in pretty bright twilight. The cool thing is that since the tail points away from the sun, it will rise first. That may be something to look for a quarter to a half hour before the head or coma rises, and in darker skies. The tail will point to the upper right of the comet’s head. This too will be something to look for after the comet passes perihelion on Thursday, except the tail will point to the upper left. I’ll have more on comet viewing for Thanksgiving day on tomorrow’s program.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Animation of Comets ISON and Encke for November 19th thru 23rd, 2013 from the STEREO Ahead spacecraft. [Image Credit: Karl Battams/NRL/NASA/CIOC]. Click on the image to start the animation.

This animated GIF image was retrieved from the NASA Comet ISON Observing Campaign website: http://www.isoncampaign.org/ Two comets are seen, the brighter is ISON and the dimmer is Encke. The two bright objects are Mercury to the left and the Earth to the right. What looks like clouds flowing past is the solar wind.

Ephemeris for Wednesday, November 20th. The sun will rise at 7:46. It’ll be up for 9 hours and 23 minutes, setting at 5:09. The moon, 3 days past full, will rise at 7:52 this evening.

Let’s see where the bright planets are this week. Venus is brilliant in the southwest after sunset. It will set at 7:52 p.m. The giant planet Jupiter will rise at 8:31 p.m. in the east northeast. It’s cruising against the stars of Gemini now. It will pass due south at 7:47 a.m. Mars will rise at 1:47 a.m. also in the east northeast. Reddish Mars is two widths of a fist held at arm’s length below and left of the bright star Regulus in Leo now. Comet ISON is now about magnitude 5, now meeting current brightness predictions, Officially naked eye, you’ll probably still need binoculars to spot it. Comet ISON is below and left of the star Spica low in the east southeast and will rise about 5:50 a.m. and be visible until around 6:30 a.m. above the planet Mercury.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Venus low in the southwest at 6 p.m., November 20, 2013. Created using Stellarium.

Telescopic view of Venus on November 20, 2013. The cloud banding will not be visible. Created using Stellarium.

Jupiter in the east at 10 p.m. on November 20, 2013. Created using Stellarium.

A telescopic view of Jupiter at 10 p.m. The moon Io is peeking around Jupiter. Up is to the top. The view in your telescope may vary. Created using Stellarium.

Ephemeris for Monday, November 18th. The sun will rise at 7:43. It’ll be up for 9 hours and 28 minutes, setting at 5:11. The moon, 1 day past full, will rise at 6:12 this evening.

The planet Mercury is now visible in the morning sky rising at 5:59 a.m. While Mercury is only 19 and a half angular degrees from the sun its direction is closer to the vertical than Venus and the other planets are in the evening sky. That situation will change in 3 months when evening planets will be favored. The star Spica will be above and right of Mercury, along with Comet ISON which will be nine moon diameters below and right of Spica, about a third of the way to Mercury tomorrow. Comet ISON will rise at 5:19 tomorrow morning. Morning twilight will begin at 6:08 tomorrow morning, but remember the moon will still be nearly full so the sky won’t be really dark before twilight begins. The Moon is light pollution you can’t get around.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury and Comet ISON at 6:30 a.m. on November 19, 2013. Created using Stellarium.

Comet ISON’s tail may be visible to the naked eye or in binoculars after it’s outburst last Thursday night. The comet may be able to live up to its advance billing after all.